Host-microbiota interactions within the fish intestinal ecosystem.

Teleost fish are in direct contact with the aquatic environment, and are therefore in continual contact with a complex and dynamic microbiota, some of which may have implications for health. Mucosal surfaces represent the main sites in which environmental antigens and intestinal microbiota interact with the host. Thus, the gut-associated lymphoid tissues (GALT) must develop mechanisms to discriminate between pathogenic and commensal microorganisms. Colonization of intestinal mucosal surfaces with a normal microbiota has a positive effect on immune regulatory functions of the gut, and disturbance in these immune regulatory functions by an imbalanced microbiota may contribute to the development of diseases. Significant attention has therefore been recently focused on the role of probiotics in the induction or restoration of a disturbed microbiota to its normal beneficial composition. Given this, this article explores the fascinating relationship between the fish immune system and the bacteria that are present in its intestinal microbiota, focusing on the bacterial effect on the development of certain immune responses.

[Health risks associated with the migration of Atlantic salmon (Salmo salar L.): an epidemiological surveillance programme in Northern Spain]. / Riesgos sanitarios asociados al ciclo migratorio del salmón atlántico (Salmo salar L.): programa de vigilancia epidemiológica en el Norte de España.

The authors present the results of an epidemiological surveillance programme involving Atlantic salmon (Salmo salar) populations in north-eastern Spain. The study investigates the risk factors critical in disease transmission, which include the presence of potentially pathogenic micro-organisms, the innate cell-mediated immune response of the salmon, and the potential interactions between the two. Also taken into account are the biological and migratory cycles of these salmon populations. The results showed that Aeromonas salmonicida and Saprolegnia parasitica were the micro-organisms that played the most important role in the transmission of the disease by virtue of their pathological characteristics, their occurrence in large numbers, and their capacity to transmit disease. With regard to the cell-mediated immune response, the authors observed a wide variability between individuals in some cell groups, as well as certain seasonal and age differences. These may be factors that predispose the animals to infection or to becoming asymptomatic carriers, with the attendant risk of transmitting infection in the course of migration. This could be especially relevant in the case of salmon infected with A. salmonicida and S. parasitica, since it has been observed that such salmon have a decreased number of leucocytes compared to non-infected salmon.

[Information program applied to the temporal study of pathological processes in animal populations]. / Programa informático aplicado al estudio temporal de procesos patológicos en poblaciones animales.

WinEpi Tasas 2.0 is a new, globally accessible computer program, which has been developed as a research tool for the epidemiological study of the pathological processes which affect animal populations. This new version of the program, based on the experimental version, WinEpi Tasas 1.0, enables users to study the distribution and evolution of diseases in affected populations, over time. This information, combined with data on spatial distribution, is of fundamental importance for the establishment of appropriate control strategies and health policies. Such disease control measures are of particular significance in the current context of emerging and re-emerging diseases. The program can be run in either English or Spanish.

Risk factors associated with the seroprevalence of leptospirosis among students at the veterinary school of Zaragoza University.

The prevalence and risk factors associated with leptospirosis were studied in veterinary students in Zaragoza. Sera were collected at the beginning and end of the academic year 1994 to 1995 and were tested by ELISA against a pool of Leptospira interrogans serovars bratislava, canicola, grippotyphosa, hardjo, icterohaemorrhagiae and pomona antigens. At the beginning of the study the prevalence was 8.14 per cent and at the end it was 11.4 per cent. The incidence of the disease during the study was 0.0394. Risk factors associated with leptospirosis included: taking the course specialising in food inspection and technology, on-farm work, contact with pets in general, and particularly carnivores, and contact with animal traders. The symptoms associated with the disease were myalgia and fever, and the treatment of the symptoms provided some protection.

Water quality parameters associated with Aeromonas spp-affected hatcheries.

This study investigates the role of water quality parameters as possible risk or protection factors in Aeromonas spp-affected rainbow trout hatcheries in northeastern Spain. The results revealed an association between oxygen concentration, ammonia concentration and total dissolved solids (TDS) with the prevalence of Aeromonas spp cases on the affected fish farms. The oxygen and ammonia concentrations acted as risk factors when their values were lower than 7.06 mg/L or higher than 0.05 mg/L, respectively, generating odds ratio (OR) values of 2.0 and 2.3. TDS levels, however, acted as a protective factor (OR = 0.39), from an epidemiological point of view but not statistically, when the values were outside the normal range, 199-261 mg/L. On a multivariate level, fish farms exposed to all the associated factors at the same time, had a risk of being affected by Aeromonas spp that was 1.74 times higher than farms with normal quality parameters; the risk increased when TDS had a normal value and it decreased when oxygen and/or ammonia concentrations had normal values.

Furunculosis control using a paraimmunization stimulant (Baypamun) in rainbow trout.

The effect of Baypamun, a non-specific immune system stimulant, on the treatment and control of furunculosis was studied in experimentally infected rainbow trout. A statistically significant association between the Baypamun treatment and a reduction in cumulative incidence of the clinical symptoms of Furunculosis and the infection level, despite the presence of the bacteria in blood and organs was observed. A reduction in the mortality rate in Baypamun-treated fish was also observed but this was not statistically significant. The results suggest that the treatment of fish diseases with non-specific immune stimulants could be, in the future, a good defense strategy leading to a reduction in disease symptoms and a greater control of the asymptomatic carriers after an outbreak.

Diagnostic survey of viral haemorrhagic disease in wild rabbits (Oryctolagus cuniculus) in four regions of Spain.

Samples of organs and serum were obtained from wild rabbits (Oryctolagus cuniculus) found dead in the field, shot or captured by hunters, or introduced for repopulation in various provinces of Spain over a two-year period, for the purposes of an epidemiological study of viral haemorrhagic disease (VHD) of rabbits. The efficacy of the haemagglutination test and the direct immunofluorescence test for the diagnosis of VHD was also examined.

Ecopathology in aquaculture: risk factors in infectious disease outbreak.

This paper describes a study of the risk factors associated with disease outbreaks in fish species of fish farms and rivers of north-east Spain. We focused our work on the isolation of fish pathogens (bacteria, virus), the water quality (physicochemical and microbiological quality) and management characteristics. We have observed 2 important viral diseases, infectious pancreatic necrosis and spring viraemia of carp, and 2 important bacterial ones, furunculosis (Aeromonas salmonicida) and bacterial kidney disease (BKD) (Renibacterium salmoninarum). Our preliminary results show that there are some potential risk factors associated with the main diseases of fish, such as fish age, fish species, production system, season and water temperature, but their role depends on the disease.

Survey of rotavirus infection in a dairy herd: comparison between polyacrylamide gel electrophoresis and two commercial tests.

A survey of rotavirus infection in a dairy herd with a history of neonatal diarrhoea was carried out. Faecal samples taken from 15 cows before and after calving as well as faeces taken from their calves daily from birth to two weeks of life were tested for rotavirus by polyacrylamide gel electrophoresis (PAGE) and compared with an ELISA and a latex agglutination commercial test. Rotavirus excretion was not detected in faeces from cows around parturition by any of the three tests. However, all of their calves shed rotaviruses during the observation period. The onset of rotavirus excretion determined by PAGE ranged from day 2 to day 8 of life (day 4.8 +/- 1.8 on average) and lasted for 4 to 7 days (5.3 +/- 1.1 days on average). Chi-square test showed a significant association (P = 0.0001) between the presence of rotavirus and the altered consistency of calves faeces. All the three tests showed similar results (overall agreement 92.5%) but discrepancies were detected mainly at the beginning or at the end of the rotavirus excretion period. Results obtained with both commercial kits closely paralleled each other and parameters other than sensitivity, specificity, diagnostic accuracy or predictive values have to be considered as selection criteria.

The effect of experimental infection with Corynebacterium pseudotuberculosis on reproduction in adult ewes.

Fifteen ewes were inoculated subcutaneously with 2 x 10(6) cells of Corynebacterium pseudotuberculosis seven days before mating, during the embryonic stage of gestation and during the fetal stage of gestation. The clinical signs, antibody response and the consequences of the infection on reproduction were studied. None of the ewes showed any change in general condition during pregnancy. The effects of experimental infection during gestation were evident after incubation periods that ranged from 25 to 140 days after inoculation and were dependent on the time of the inoculation in relation to the period of gestation. Ewes inoculated before gestation can resolve infection. Ewes inoculated during the embryonic stage were severely affected and some aborted. In others lambs were stillborn or, if born alive, infected. Ewes inoculated during the fetal stage of gestation did not show reproductive disorders although some remained chronically infected.

Aganglionosis del colon. / Total colonic aganglionosis

Se presenta la experiencia del Hospital de Pediatria del C.M.N., en cuatro pacientes con aganglionosis total del colon. Se hace hincapie en el diagnostico oportuno y se valora el resultado obtenido con la tecnica de Lester-Martin. En los dos pacientes en quienes se practico esta, las pruebas de absorcion intestinal demostraron deficit para la vitamina B12 y grasas, encontrandose el resto dentro de la normalidad.Son continentes y su desarrollo y crecimiento estan ligeramente abajo de lo normal

Tumores de glandulas salivares en ninos. / Salivary gland tumors in children

En nueve casos de tumores de glandulas salivales en pacientes de edad pediatrica, se encontro que el sexo femenino y el lado derecho del cuello fueron los mas afectados. El tumor mixto fue de mayor frecuencia con cinco casos, encontrandose tambien un caso de carcinoma de celulas acinares y uno de carcinoma mucoepidermoide, ademas de un hemangioma y un hemolinfangioma. Los datos clinicos principales para el diagnostico fueron, presencia de tumoracion en los benignos y en los malignos ademas de esta, dolor y alteraciones del nervio facial. Los estudios de gabinete de mayor utilidad para el diagnostico fueron la sialografia y la termografia. El tratamiento fue quirurgico con reseccion total de tumoracion respetando siempre el nervio facial. Los resultados a largo plazo son muy satisfactorios obteniendose un 90% de curacion. Ni radioterapia ni la quimioterapia tienen indicacion terapeutica en ese tipo de tumores

Megacolon congenito: resultados de su tratamiento quirurgico. / Congenital megacolon: results of its surgical treatment

En un grupo de 41 pacientes estudiados con diagnostico de megacolon congenito, se encontro una relacion de 2:1 para el sexo masculino; el diagnostico se establecio de acuerdo a los datos clinicos, manometricos radiologicos y, en forma definitiva, de acuerdo a los hallazgos histologicos. En 24 pacientes se realizo la tecnica de Duhamel-Grob, con resultados satisfatorios en 22 y regular en 2. Las complicaciones mas frecuentes fueron estenosis de la anastomosis y absceso de la herida abdominal. La mortalidad global fue del 29%; estos pacientes fallecieron por septicemia antes de poder realizar el tratamiento quirurgico. De acuerdo a los resultados obtenidos, la tecnica de Duhamel-Grob para el tratamiento de la enfermedad de Hirschsprung es una de las mas adecuadas

[Surgical management of intestinal atresia]. / Conducta quirúrgica en atresia de intestino

The study included 33 newborns with the diagnosis of intestinal atresia after discarding those of the duodenum. According to the clinical conditions of the patient and of the malformation, surgery was carried out by derivative ileostomy or primary anastomosis. Survivorship reaches 67% for ileostomy and 65% for anastomosis which are much higher figures than those obtained before.